Server Not on Steam List

[EmoMidget]

My server does not show up on the steam server list. I have posted about this on many other forums, but never got an answer that worked. My friends can connect by adding it to their favorites or using the console command, but none of us see it on the steam list. I dont have a firewall or anything, so thats not the problem. I have a router, but the ports are open. What can I do to get on the list?

[Spartanfrog]

Try DMZing it.

[EmoMidget]

What does that mean?

EDIT: I was reading other posts about this, and one said Linksys WRT54G does not allow your server to be added to the master list. Right now Im using WRT54GS. Could that be the problem? Is there a way to fix it? If it cant be fixed, what router would work?

EDIT: I did the DMZ thing in my router, and added heartbeat to my server.cfg. One of my friends said he saw it, but my other friends said its not there. Can one of you test it?
The map is zm_lila_panic
ServerName: Zombie - Death Cult Armageddon

EDIT: I forgot to say that my server shows up in gametiger.net. Would that mean its working? I dont get it...

[Drocona]

If it shows on gametiger it works, that's coming directly from the masterserverlist

If you use the search you would also find that people with that router download and install "custom" firmware to fix the problems.

[EmoMidget]

Alright, thank you